Blood pressure monitors



May 16, 1967 Filed July 13, 1964 BLOOD PRESSURE MONITORS S. B. LONDONF/G. I

AMPLIFIER BLEEDER IGURM CUFF) 3 sheets-sheet 1 N O K10 QOUDOCOQUoOa24(MAN0METER) M (SIGNAL LAMP) ATTORNEYS May 16, 1967 s. a L @NDON3,39,623

BLOOD PRESSURE MONITORS Filed July 13, 1964 3 Sheets-Sheet 2 QGVDSSSAMPLIFIER 3s K49KBM6VDCM GV- OCS i6( AHM 36 (MICROPHONE) novAc5 PUMPINVENTOR SEYMOUR B. LONDON F/G. 2 www (v3/Sgam' ATTORNEYS May 16, 1967s. B. LONDON 3,319,623

BLOOD PRESSURE MoNToRs 3 Sheets-Sheet 5 Filed July 1s, 1964 AMPLIFIER 38swzosvocss SWZOGVDCSG swzaevocs? INVENTOR SEYMOUR B. LONDON UnitedStates Patent O 3,319,623 BLOOD PRESSURE MONITORS Seymour B. London, 35E. Dilido Drive, Dilido Ave.,

Miami, Fla. 33139 1 Filed July 13, 1964, Ser. No. 382,255 13 Claims.(Cl. 12S-2.05)

The present application relates to blood pressure monitors and inparticular to mercury column manometer and aneroid manometer monitorsfor determining and Visually presenting systolic and diastolic bloodpressure readings, and in a continuation-in-part of my copending-application which issued August 24, 1965 as U.S. Patent No. 3,202,148.

To gain a proper appreciation of the scope of invention of the bloodpressure monitors disclosed herein and to properly understand theproblems inherent in distinguishing different types of blood pressuredetermination, the following background of historical medical eventsrelating to blood pressure determination is presented herewith:

SYSTOLIC AND DIASTOLIC Systole is the forceful contraction of the heart.Acting as a pump each contraction of the heart ejects into the aortaabout 60 cc. of blood which produces a wave of blood through thearterial system. The crest of this pressure wave is called systolicpressure. Diastole is the period of relaxation of the heart when theheart iills with blood. The diastolic period of the pressure Wave is thetrough of the wave; that is Ia point of minimal pressure coinciding withthe resting phase or diastolic phase of the heart. The mean pressure ofthe arterial systern is usually given as one-half of the sum of value ofthe systolic and diastolic pressures but may be slightly lower.

Pulse pressure is the Ldifference between systolic and diastolicpressures. For instance, if the blood pressure were 120 systolic and SOdiastolic, the pulse pressure would then be the difference between 120and 80 or 40 millimeters of mercury.

The pressure in the arterial system depends upon several factors:

(1) The pumping -action of the heart forces blood into the arterialsystem.

(2) The peripheral resistance of the arterial system. This is determinedby the caliber of the small blood vessels which respond to stimulationof the controlling nerves with constriction or relaxation, thusregulating the rate of the outow of blood from the arterial system intothe capillaries and Veins.

(3) The -amount of blood in the arterial system also contributes to thepressure inasmuch as the blood vessels are elastic, the vessels must belled to capacity before there is any blood pressure and then overilledto slightly distend the walls to elevate the pressure to the normalphysiologic limits. It is this distention of the elastic Walls of theblood vessels which produces blood pressure. The diastolic pressureprovides for a uniform flow through the small blood vessels andarterioles.

DIRECT MEASUREMENT The earliest and perhaps the most complicated methodof measuring blood pressure was the direct method. In this method aneedle is introduced directly into the artery and by appropriateconnection, a transducer is used to relate the pressure in the artery toa graph or other form 3,319,623 Patented May 16, 1967 ice of recordingdevice. Of the various direct systems the optical method, the rst methodused, simply consisted of a mirror attached to a membrane or tambourthat uctuated with each pulse as it was transmitted up the needlethrough a -rigid tubing. This fluctuation was inscribed by photographicmeans on a recording surface. Conclusions could be drawn as to therelative pressure in the arterial system by properly standardizing theequipment. The electrical transducer, a little more sophisticated,consists of three basic varieties:

(a) Condenser, (b) Strain gauge, and (c) Inductance type of transducers.

Here the fluctuations of pressure create variations in electricalvoltage and by quantitating the electrical current and Voltage, ameasure of the pressure variations can then be obtained. It is generallyconceded that the accuracy of the direct blood pressure determination isquite good with errors of plus or minus 5 millimeters of mercury beingconsidered acceptable.

INDIRECT MEASUREMENT The indirect method of blood pressure determinationmeasures the lateral pressure of the arterial wall as opposed to the endpressure as measured by the intraarterial needle in the direct method.

1) Palpaton of pulses-About 65 to 70 years ago one of the physiologistsin Italy by the name of Riva- Rocci devised the blood pressure arm cuifand manometer as we presently know it. By this means the pressure in thecuff acting as a tourniquet on the arm is increased until the blood flowin the artery beneath the cufr" is obstructed. At this point no pulse ispalpable below the constricting cuff. By rst constricting the arterythen feeling for the pulse below, while observing the manometer, thefirst pulse felt after the constricted artery was released wasindicative of the height of the blood pressure wave or systolicpressure. Generally, this pulse was felt about 8 to 12 millimeters belowtrue arterial pressure and while it served as a crude guide it had muchto -be desired from a point of view of accuracy and direct relationshipto the arterial pressure.

(2) Auscultaton or sounds.-In 1905 the Russian physiologist, Korotkow,made observations which are of eX- treme importance in clinical medicinetoday. He found that under ordinary circumstances while listening with astethoscope placed on an artery, no sounds were heard. Therefore, heconcluded that the flow of blood along arterial channels was inaudibleto the human ear despite the fact that you could feel .a pulse. If theartery was compressed by the cuff attached to a manometer so as tocompletely arrest the flow of blood, no sounds were heard below thecompression, but when the compression of the artery was slowly released,a sharp tapping sound could be heard in rhythm with the heart beat byallowing the pressure in the cui to fall just enough so that a smallamount of blood could pass beyond the compression point. These soundsbear the name of the original observer and are called Korotkow sounds.They are found over a range of .approximately 40 to 50 millimeters ofmercury and then disappear. They cannot be heard below the diastolictrough of pressure. Therefore, the rst sound that is heard Vindicatessystolic pressure and the last sound heard indicates diastolic pressure.The difference between the systolic and diastolic pressure is againgiven as pulse pressure. Thus, one must distinguish the Korotkow soundsheard as opposed to pulses because while the sounds could noz be heardbelow the diastolic pressure, the pulses could easily be palpablewithout any compression of the artery.

(3) Small vessels ndces.-The auscultatory method is used in present-daymedicine to determine the indirect blood pressure. The third method ofindirect blood pressure determinations which has proved to be of someinterest in laboratory investigation but has little clinical value, isthe electrical recording -of pulse variations either `distal to an armcuff or by transducer directly connected to a linger cui. Changes insuch .a plethysmograph type of tracing have been recently devised andmodified so that pulse changes can be picked up by a photoelectric celltransducer attached to the ear or linger. Generally these methods havenot been reliable because they attempt to detect blood pressure changesonly in the small blood vessels and reiiect mainly volume and ow typechanges in the part (linger, etc.) rather than a true intra-arterialpressure change.

Numerous patents, such as that granted to Williams et al. (US. PatentNo. 2,352,875), disclose the use of the `above-mentioned auscultatorymethod to determine indirect blood pressure. There is, however, noevidence that the Williams instrument has ever measured anything7 excepta pulse detected via a Wrist culi". The Williams machine determinespulses by pressure variations in the culi touriquet depending on asuccession of diastolic pulses to indicate that the diastolic pressurehas been reached. Physiologists, who have studied this problem, feelthat this type of determination could not give an accurate end point andis merely representative of pulsatile expansion to the artery ratherthan diastolic pressure. Comparative studies with intra-arterialpressure determinations by means of strain gauge manometers and othermeasuring devices reveal a -great discrepancy between the pulsatilephenomena as detected 4by a blood pressure culi and the diastolic bloodpressure. The present invention constitutes a substantial improvement inthis iield since determinations of the diastolic pressure are made bythe established principle of indirect blood pressure determination usingthe disappearance of the Korotkow sounds as the simultaneous end pointof diastolic blood pressure. Fur- ,therthe detection lof Korotkow soundswithin a range of 2% mm. Hg is contemplated by the invention disclosedherein. That is, since this invention is designed to detect and registerdifferences of pressure in units of 5 mm. of Hg, the units sensitivityis i2.5 mm. of Hg.

Since the unit measures and registers the blood pressure objectively inunits and `by techniques employed universally, i.e. the recognition ofthe level of the first and last blood pressure sound, its use inepidemiological studies suitably oiiers comparative informationavailable for analysis. Indices of the prior art are unsuitable forcollecting and comparing epidemiological data as they do not measure thepressure of the brachial artery.

It is further submitted that the present invention constitutes asubstantial improvement over the Pigeon (U.S. No. 2,821,188) and Gilford(U.S. No. 2,827,040) patents, which disclose sphygmomanometers havingseparate circuits used to convert pressures to electrical signals as thepressure drops from systolic to diastolic, since neither -of thesepatents discloses limiting means for actuating indiciaat times whenKorotkow sounds are detected.

The present invention, then, distinguishes from the prior art devices inits unique capability of performing the following separate functions:

(l) Measurng.-Continuous intermittent registration of the indirect bloodpressure on a read-out panel at intervals which can -be varied at will.

(2) Monitoring-Alarm signal or other electrical devices as might be usedto resuscitation can be activated if the blood pressure falls below'orrises above a prescribed level which can be varied by a selector switch.

(3) Programming of treatment.-Intravenous infusion of medication toraise and lower pressure can be com-V pletely automated by closed loopsystem and pressures of mercury in the column, means for selectively andin-AY dependently activating the visual indicators as the Korotkowsounds are detected.

Still another object of invention is to provide in a blood pressuremonitor device, of the type having an aneroid manometer and visibleindicators correlative to air pressure within the manometer, means forselectively and independently activating the Visible indicators as theKorotkow sounds are detected.

Still a further object of invention is to provide in a blood pressuremonitor device means for separately registering indirect blood pressureon a read-out panel at variable intervals, activating an alarm systemwhen blood pressure falls below or rises above a prescribed level, andprogramming of treatment.

Yet additional objects of invention will become appar-V ent from theensuing specification and attached drawings wherein:

FIG. l is a schematic View of blood pressure monitor with cuff 16 andmicrophone 36 aixed adjacent the brachial artery;

FIG. 2 is schematic view of mercury column blood pressure monitor andappropriate circuits;

FIG. 3 is schematic view of aneroid manometer blood pressure monitor andrelated circuits; and

FIG. 4 is schematic view of the programming and alarm system used inconjunction with either mercury column or aneroid manometer bloodpressure monitors.

As seen in FIGS. 1 and 2, the basic component parts of the mercurycolumn manometer blood pressure monitor consist of a circuit actuatingpush-button 10, pump 12,

arm cuff 16, manometer 24, bleeder valve 28, solenoid valve 31,microphone 36, amplifier 38, contact points C2 through C53, relays K1through K47, signal lamps'30, 35 40 255, systolic limiting switch 2i)and diastolic terminating switch 32.

The operation of the mercury column blood pressure monitor is asfollows:

As seen in FIG. 2, the closing of the volt A.C. circuit Iby push-button10, initiates the pump 12 action through 110 volt A.C. line 6 in contactthrough Vthe normally closed contacts of relay K1 with 110 volt A.C. 7.The pump acts as a compressor inllating the arm cuff 16 and at the sametime through tube 15 connected by a T- tube connection 17 with tube 14compresses the chamber" 44 of the manometer 24. The increase in pressurein the chamber 44 will force the mercury column 26 up establishing amercury contact to the various contact po-ints on the contact column 52.Because contact 25 is connected to the minus side of the 6 volt D.C. bylines DC69 and 6 volt DC70 the circuit is closed between the variouscontact points C2 through C53 and the -6 volt D C. supply, as long asthe mercury is in contact with these points.

The pressure of pump 12 continues to force the mercury column 26 up tocontact C53,` which is connected by line KIC, DC7 and KlC, DC6 to thecoil of the three pole 6 volt D.C. relay K1. The mercury 26 contact actsto close the circuit to the coil, which is supplieddirectly on thepositive side by the lines 6 volt D.C. 1, 6 volt D.C. 3, 6 volt D.C. Sconnections. Pole I of K1 relay connected by line 6 volt D.C. 4 toground, in the active position supplies through its normally opencontacts 6 volt D.C. through line 6 volt D.C. 10 to the positive side ofthe coils of relays K2 through K47 and including solenoid valve 30(KS2). As soon as pole I circuit of relay K1 is closed the isolatingrelays K2 through K47 are pulled into the active position by closure oftheir respective circuits by virtue of the contact of the mercury columnto contacts C2 through C53 and their connections to lines DC11 throughDC56. Pole Il of K1, normally open contacts, are connected to thenegative side of the 6 volt D.C. supply, through connection with lineDC68 through the normally open contacts of sensitive relay K55. Byestablishing contact with line DC11 through lines DC6, 8 and 9, pole Ilprovides a hold for the coil of K1, so that the relay K1 is maintainedin an active position. The second pole of relay K1 through line 6 voltD.C. 9 is also connected to switch 20. Switch 20 is a systolic limitingswitch and performs a function of shorting from contact S3 to contact 41and contact 37 and contact 33, as will be further described. Pole IH ofK1 through the ll() volt connection of AC6 and AC7 in the normallyclosed position, supplies 110 volt circuit to the pump 12, until relayK1 coil is closed (interrupting the 110 volt circuit and discontinuingthe pump action). Following interruption of the pump 12 circuit, slowdecompression of the cuff 16 and the chamber 44 of the manometer 24occurs simultaneously as a result of the bleeder valve 28. With the dropin pressure in the chamber 44, the mercury column 26 will drop at acontrolled rate of 21/2 to 5 mm. per second.

In the upper right hand corner of the schematic is the amplifier 38whose input is connected to microphone 36 held in the arm cuff 16. Thepower supply to the amplifier is through line 9 volt D.C. 1 and anadditional 9 volt D.C. battery by 9 volt D.C. B1. With the detection ofa Korotkow sound by microphone 36, held in place over the artery on thearm, amplication through the amplifier 38 circuits by transistors 1, 2,3 and 4, would cause sensitive relay K49 to pull in to an activeposition. This creates a signal by virtue of the connections of linesDCS9 and DCSS with the normally open contacts of relay K49. DCSS leadsto the normally open contacts of relay K2 which corresponds to aposition of 255 mm. of Hg (CS2) and since the mercury column 26 is stillin contact with CS2, K2 will switch the 6 volt signal through itsnormally open but now closed contacts to signal lamp 255, causing signallamp 255 to ash simultaneously with each pulse and Korotkow sound heardin the artery above 25 5 mm. of Hg.

As the mercury column 26 descends due to the action of bleeder valve 2Scontact of the mercury with contact CS2 is lost, K2 coi is interrupted,and the normally closed contact of K2 will switch the signal of line 6volt D.C. S8 to the normally open, but now closed contacts of K3.Pressure sounds detected by the microphone with the mercury column 26 atthis contact point, will close the circuit of the memory relay coil K3M.Providing a connection between this side of the coil of memory relaywith line 6 volt D.C. 60 by the normally open contact will result in ahold7 action to the coil and the K3M relay will remain in an activeposition. Since signal light 259 is parallel to K3M coil, the signallight will remain illuminated as long as the coil is in an activeposition. Similarly, as the mercury column descends, K3 coil will becomeinterrupted when contact of the mercury column 26 to CS1 is interrupted.The normally closed contacts of K3 will switch the signal to thenormally open, but now closed contacts of K4, which in turn will closethe circuits to the K4M memory relay and signal light 24S will becomeilluminated upon detection of a signal by microphone 36.

As the mercury column 26 drops, each subsequent isolation relay (K3through K47) switches the signal circuit and contact to its companionmemory relay, K4M through K47M, only while its own coil is closed by theconnection to the mercury column. As each isolation relay coil isinterrupted, its normally closed contacts switch the signal from themicrophone (through K49 to DC58) to the next relay with the closed coilat the top of the mercury column. Thus each relay isolates the signal sothat the signal is transmitted only to its companion memory relayilluminating the signal lamp that corresponds to the millimeters of Hgat which the sound was detected. A signal produced at any other timeexcept for this sensitive or receptive period has no eiect on any lofthe memory relays. Since the level of the blood pressure corresponds tothe level at which sounds in the artery are present, the signal lampswill become illuminated and give a read out of the blood pressure.

Switch 32 is a diastolic termination switch, so that after diastolicpressure has been established, the cuff can rapidly be decompressed toatmospheric pressure. Since in individual patients diastolic terminationmay be desirable at different levels, the choice between 90, 70 and 50,30 mm. of Hg is oiered by contact points 7, 11, 15 and 19. Switch 32through line DC78, 77, 76 and 75 with contact t-o DC64 provides thenegative side of the coil of relay KS3 with a closed circuit. Thepositive side of the coil of KS3 is to ground so that KS3 will remain inan active position until the dropping mercury column opens the circuitof coil of relay KS3 through switch 32 and through line DC64.

During its active state, pole II of relay KS3 acts to charge capacit-orC8 of the time delay. When capacitor C8 is charged, transistor Q of thetime delay circuit will conduct and maintain the normally open contactsof relay KSS closed. When transistor Q ceases to conduct by virtue ofdecay of the charge of capacitor C8, the contacts of relay KSS open andthe minus side of the 6 volt circuit is interrupted, the coil of K1 isopened and the entire cycle is re-started. Pole I of relay KS3 throughthe normally closed contacts, closes the circuit to solenoid valve 39(KS2) and rapid decompression of the arm cui 16 and mercury chamber 44occur. The positive side of solenoid valve 39 (KS2) is through lineDCS7, thus the solenoid valve will be held in an active position, i.e.,valve is open, until the 6 volt D.C. circuit is interrupted by K55through the time delay mechanism. The length of time that the time delaymaintains the normally open contacts of KSS in a closed position dependsupon the capacitor 8 charge. When capacitor 8 is charged, because Q, thetransistor in the time delay is an NPN configuration, conduction throughthe transistor will occur. Relay K55 is a sensitive relay and will beactivated by conduction through the transistor. The duration ofconduction through the transistor controlled by switch 34 which, byvirtue of R12, a variable resistor can regulate the rate of decay byincreasing or decreasing the resistance.

Switch 32, the diastolic limiter switch, in eect, then controls theAsolenoid valve 39 through pole I of relay KS3 and also starts the timeor interval delay mechanism in operation through pole I Switch 20similarly performs a function of limiting the level of rcompression ofthe arm cuff 16 and the mercury manometer 24, so that by the connectionswith lines DC71, 72, 73 and 74 to contacts 27, 33, 37 and 4.1respectively, inflation of the cuil to 130, 160, 180, 20() or 250 mm. ofHg can be selected. Systolic limiting switch 20 establishes a contactbetween C53 `which corresponds to a level of 260 mrn. of Hg and eithercontact 41 corresponding to 20() mm. of Hg or contact 37, 180 mm. of Hgor contact 33, 16() mm. of Hg or contact 27, 130 mm. of Hg.

As seen in FIG. 2, the basic component parts of the aneroid manometerblood pressure monitor consist of pump \12, arm cuff 16, the aneroidmanometer 24A (comprising chamber 44A, Contact arm 26A, pistonarrangement and eccentric gears 91 and 92), bleeder valve 7 28,microphone 36, amplifierA 38, contact points C1 through C53, relays K1through KS4, signal lamps 30, 35, 40 25S, systolic limiting switch 20and diastolic terminating switch 32.

The operation of the aneroid rnanometer sure manometer is as follows:

By virtue of the connection of the 100 A C. 7 and 110 A.C. 8, the pumpaction is initiated and pump 12 through tubings 14 and 15 simultaneouslyinflates the arm cuif 16 and at the same time compresses air into thechamber 44A of the aneroid manometer 24A. As Ithe pressure is increasedin the chamber 44A, a piston arrangement 90 rotates an eccentric gear 91which because of its ratio to the gear 92 rotates the contact arm 26Afrom its zero position in a clockwise direction. The 6 volt D.C. currentreduced and rectified through transformer number two by a lead from theminus side of the 6 volt D.C. power supply labeled 6 volt D.C. 60 is ledto relay KS4 and the normally closed contacts of KS4 allow the circuitto continue rvia 6 volt D.C. 59 connection to 6 volt D.C. 50 leading topoint 25A which is a contact point supplying the arm 26A closing circuitfrom 26A to the various contact points. The arm 26A would continue torotate until contact 53, which corresponds to a pressure of 260millimeters of mercury, is reached. At this point through 6 volt D.C.lines 53, and 6 volt D.C. 52, the coil of relay K1 is closed since 6volt D.C. 51 is connected directly to positive pole or ground.

Relay K1 is a three pole relay. Pole \1 connected by 6 volt D.C. 2 and 6volt D.C. 1 to ground supplies 6 volt D.C. by line labeled 6 volt D.C. 3to the isolating relays as soon as K1 is in the active position. Pole 2by virtue of its connection -to 6 volt D.C. 53 through 6 volt D.C. 5Sline supplies the negative leads 'which maintains K1 in a closedposition by D.C. 59 connection with 6 volt D.C. 60. Through the contactsof relay KS4 the circuit is opened by activation of relay KS4 at thetermination of the cycle. Pole 3 of K1 throughthe 110V volt A.C. 6 inthe normally closed position supplies 110 volt circuit to Athe pump byAC7 until K1 is pulled into the active position and the circuit to thepump interrupted.

Following interruption -of the pump circuit, decompression of the cuff,and the chamber 44A occur simultaneously as a result of bleeder valve 28which allows a slow escape of air rotating the arm 26A on the face ofYdial 52A countercloclwvise from contact 53 to 52 to 51 etc. down tocontact 1, establishing a contact at each of these contact points. t

In the upper right hand corner of the schematic is amplier 38 which isconnected to microphone 36. It is supplied by a 9 Volt lead DCI plusIthe small 9-volt transistor battery labeled B. As illustrated when aKorotkow sound is detected, amplification 'by transistors l1, 2, 3, and4 occur after filtering etc. pulls into an active position. With thedetection lof the Korotkow sounds by microphone 36, a signal is createdby K49 as the minus 6 volt lead D.C. 63 leads through the closedcontacts Iof K49 via DC62 to the contacts of relay K2. Relay K2corresponds by virtue of connection DC4 to contact C52 Ito a position of255 millimeters of mercury. If this signal is present because thenormally open circuits of K2 are closed when lever arm 26A is at contactpoint C52, a signal lamp 255 will be illuminated as a ash. As thedecompression of the cuff and chamber occurs simultaneously, signal arm26A will slowly rotate down or counterclockwise lby virtue of gears 91and 92 from contact 52 to contact 51 and relay K3 will, because of itscontact to 6 volt D.C. 5, pull linto the active position. A Korotkowsound received at microphone 36 is switched through the normally closedcontacts of K2 through the normally open but now closed contacts of K3(closing the circuit of the isolation relay to the memory relay K3M).The KorotkowV sound received at .the microphone which closes the signalcircuit by relay K49 will thus activate the relay of K3M, cause K3Mconblood presand K49 the sensitive relay Y further sounds are heard, and

tacts to close, which in the closed position will form a lock or hold byvirtue of the common supply to N.O.

contacts and to the coil of K3M by WC61. Signal light 250 will thereforealso become illuminated simultaneously since in essence it is parallelto the coil of K3M. Thus,

as the arm rotates to ythe next contact point represented p by C50 at245 millimeters of mercury, relay K4 'will,

in turn, become active as the coil K4 is closed yby virtuel at any othertime relays.

As the arm rotates each'subsequent signal Vlamp is illuminated until thediastolic level is reached. Since no despite the fact that eachsubsequent isolation relay is activated, no further signals areproduced. When the contact arm rotates to zero position by contact andconnection DC82, relay KS4 is activated. When relay KS4 is activated,the circuit to the minus side of the power supply is opened throughleads DC59 and DC60. This in turn releases the hold mechanism for K1,all the signal lights are turned otf because of the interruption of thehold relays K3M to K47M and the cycle restarts when the normally closedcontacts of pole 3 close the 110 volt circuit for the pump 12.

Switch 32 provides a diastolic termination regulator so that after thediastolic pressure has been established the cuff can rapidly avoidingdiscomfort and irritation of the sensitive tissues of the arm. This isaccomplished by switching system is decompressed to zero atmos- Becausethe contacts of switch 32 alis supplied by pole 2. Pole 2 through theN.C. contacts by 6 volt D.C. 73 supplies a positive lead through 6 voltD.C. 74 to the positive side of the capacitor in the time delay circuitthus charging the cap-acitator.

Because of the NPN configuration of Q, a positive charge will produce owin the NPN transistor Q and relay K55 will pull in, interrupting thecircuit supplied by DC67 to the contact points of K55. Because of a holdcontact arm 26A returns to C`1 position, the coil of KS3 remains closedinterrupting the pole of KS4 opening the circuits fromrthe 6 volt powersupply lead 60 and 59. As indicated earlier, this immediately restartsthe entire cycle. As in our previous descriptions 52A is a plastic facewith the contacts superimposed and isolated from each other. The sideview of the plastic face and the contacts and the contact arm 26A isprovided to the right of the schematic. Contact 25A lis alsodemonstrated.

In addition to the diastolic terminating switch 32 there is a systolicterminating switch -or a systolic limiting switch 20. The purpose ofswitch 20 as illustrated is to establish a contact between C53 whichcorresponds to a level of 260 millimeters of mercury, Oil-correspondingto 200 millimeters of mercury, C37--180 millimeters of mercury, CSS-160millimeters of mercury, C29-130 millimeters of mercury. By this switch20 the pump compression of the arm cuff and chamber can be terminated atany of these points once it is determined that useful range ofmonitoring is accomplished by .a lower level than 260 millimeters ofmercury.

The electrical circuitry for the programming Yand alarm system. as shownin FIG. 3, is initiated by relay KS3 (in both FIGURES 1 vand 2). Uponcompletion of measuring cycle, rapid decompression of the cuff isaccomplished by closing the coil of relay KS3, a double pole relay. PoleII through its N O. contacts supplies a 6 v. D.C. positive supply in theactive poosition to coils of the relays and solenoids of the alarm andprogramming systern, K75, K76, K77, K78, K79, K8() and the positiveterminal of alarm buzzer B115. The negative leads to close the variouscircuits originate with the terminal contacts of the circuits oi' thememory relays K3M through K47M as illustrated in FIGURES 1 and 2.

For this type of therapy programming a range of 20-30 points millimetersof mercury is desirable and contact points to the left of the read-outpanel, a to c, d, e, f, corresponding to 60 thru 150 mm. Hg wereselected for shock treatment programming with g, h, z', j, k, l pointscorresponding to 130 to 220 mm. Hg for high blood pressure treatmentprogramming. Each of points a thru f will close circuits only if theirrespective memory relay coil is open, points g thru l will closecircuits only if their respective memory relay circuits are closed.Between 120 and 150 mm. Hg, the two types of programming overlap withoutinterferences.

Automated closed loop feed back high blood pressure control andtreatment is directed to the regulation of the amount of certainmedications introduced by the intravenous tubing into the blood stream,dependent upon the level of blood pressure (FIGURE 3), flask 101 and 102contain stronger and relatively weaker concentrations of the medicationsrespectively. In essence the treatment program depends on the ability tocycle olir and on either ilask 101 or 102 depending on the bloodpressure control point selected. Selector switch PAI and P2 regulatelevels at which the medications in asks 101 and 102 are available forintravenous therapy. PA1 diers from PA2 only inasmuch as PAI soundsalarm in addition to programming therapy when its circuit is closed.Switch 120 closes the circuit to the alarm buzzer B115. It is parallelelectrically to the coils of relay K75, a disconnect relay. The twosystems are coordinated so that PAI will `automatically supersede thecircuitry of P2 through the disconnect relay of K'75 since the lead fromswitch P2 to flask 102, solenoid valve 106 (K78) is through the normallyclosed contacts of relay K75 by means of leads DC124 and DC134.

Two contact points, one 20 mm. below the other are programmed .as asequence, l and k, k and j, j .and l, l and h, h and g, each willfunction to cycle ask 102 on, if the blood pressure reading on themanometer coordinates with the contact point from the switch P2. If theblood pressure continues to move up another 2O` mm. Hg, ask 102 iscycled off, flask 101 will be automatically cycled on and treatment willproceed through the tubing T1, T5, T9, T11 allowing uid into the vein112.

A sample response to therapy can be illustrated as follows: With PAI setat 220 and P2 set Vat 210 and switch 120 closed, if after the iirstmeasuring cycle the pressure is registered on the panel at 210 mm. Hg,by means of leads DC124, 134, the circuit to solenoid valve 106 (K73) isclosed. The closing of the circuit to K78 pulls open solenoid valve 106allowing the iluid in the ask 102 to flow into the vein and treatment isstarted. If upon completion of the next measuring cycle of the bloodpressure manometer, the blood pressure continues elevated and 220 mm. Hgis registered, the circuit of PA1 is closed by contact 1, 6 v. D.C. 121,6 v. D.C. 122 to the solenoid valve (K77) of flask 101. Not only willflow start in flask 101 through tubing T1, T5, T9, T11 butsimultaneously through 6 v. D.C. 123, 6 v. D.C. 128, 6 v. D.C. 130, thealarm B will sound and through 6 V- D.C. 129, the coil of K75 will beclosed interrupting the circuits of solenoid valve 106. The iluid inflask 101 will continue to run into the vein until the next automaticblood pressure measuring cycle. If the blood pressure responds to themedication and drops below 220, ask 101 will be cycled to the Offposition and the circuit to flask 102 will automatically be closed .andsolenoid valve 106 opened. Thus the elevation of blood pressure abovethe preselected point, in this case 210, instituted therapy with flask102, continuation of blood pressure elevation to 220 mm. Hg startedflask 101, discontinued flask 102, and sounded alarm B115. Return ofblood pressure to levels below 220 discontinued treatment by flask 101,restarted iiask 102, and discontinued the buzzer alarm B115. Uponresponse of blood pressure to below 210, both ask 101 and ilask 102 willbe discontinued. By moving the switch clockwise blood pressure controlcontact points labeled I to g on FIGURE 3 can be selected toautomatically maintain relatively stable and constant blood pressure ata medically desirable level using appropriate concentration ofmedications in asks 101 and 102.

The lower portions of FIGURE 3 diagrammatically illustrates theprogramming of the monitor to automatically control treatment ofdangerously low blood pressure such as may be seen in heart conditions,injuries, burns, etc. For low pressure, switch is opened and switch 130closed the control switches P3 and PA4 are positioned t0 the desiredcontrol points. Control programming switch P3 and programming alarmswitch PA4 `are interlocked and coordinated providing two controlcontact points, one 20 mm. Hg below the other, programmed ,as asequence. When switch P3 circuit is closed, flask 103 will instituteintravenous corrective treatment. But if the pressure drop to the nextcontrol point, P3 is superseded by PA4 and ask 104 replaces 103 astreatment.

In a patient, whose blood pressure should be maintained `at 110 mm. HgP3-PA4 is rotated clockwise to position c corresponding to 110 mm. Hg inthe P3 circuit and 90 mm. Hg in the PA4 circuit. Following the bloodpressure measuring cycle of the automatic monitor, no action will ensueif the read-out panel lamp corresponding to 110 mm. Hg remainsilluminated. If on the next determination there is a drop in bloodpressure to levels less than 110 mm. Hg, i.e. 105 mm. Hg the circuitryof P3 is closed, 6 v. D.C. 112, 6 v. D.C. 117, 6 v. D.C. 125 through thenormally closed contacts of pole II of relay K76 and 6 v. D.C. 133,close the coil of K79 of solenoid valve 107, opening solenoid valve 107and allowing the medicated contents of ask 103 to tlow through tubingT3, T7, T10, T11 and into the Vein 112. If this therapy is adequate theblood pressure again on the next cycle will be back to its originallevel of 110, P3 circuits will be open and treatment by flask 103discontinued through the closing of the solenoid valve 107 to itsnormally closed position. If, however, on the next measurement cycle thepressure drops below 90 mm. Hg the circuit of the programming -alarmswitch PA4 will be closed. Leads 6 v. D C. 126, 131, 132 close the coilof K76 a two-pole relay, whose pole I normally closed contacts areopened, opening the circuit to flask 103 returning solenoid valve 107 toits normally closed position. Pole II of Arelay K76 normally opencontacts close the 110 volt A.C. circuit to the ECG monitor(commercially available). Simultaneously institution of therapy withcontents of flask 104 replaces flask 103 closing the circuit to KSU,controlling solenoid valve 108, allowing the iluids to flow through thetubing T4, T8, T10, and T11 into the vein 112. With the onset of therapywith flask 104 the buzzer alarm B115 continues to ring until manuallydiscontinued by switch 130 or until the next automatic measuring cycle.If the blood pressure on the next cycle is registered at 90 mm. Hg,switch PA4 circuit remains open and switch P3 circuit will be closed.Flask 103 will be restarted for treatment into the vein, ask 104,electrocardiogram monitor and alarm B115 discontinued. .Thus ask' 103and 104 in essencercycle olf and on depending on the level of the bloodpressure and the setting7 selected on switch P3 and PA4, controllingabnormally low dangerous level by an automated closed feed back system.

Manifestly, various substitutions of parts and changes in circuitry canbe adopted without departing from the spirit and scope of inventiondefined in the subjoined claims.

I claim:

1. A blood pressure monitor apparatus comprising:

(a) an inflatable cuff;

(b) pump inflating means including a conduit' in communication with saidcuff; Y

(c) a bleeder valve positioned in said conduit to allow said cuff to sodecompress;

(d) an electrically conductive pressure responsive aneroid manometer incommunication with said conduit;

(e) a display panel electrically connected via a series of independentcircuits to respective pressure gradient contact points adjacent saidaneroid manometer, said display `panel including Visual indicia meanscorresponding to mid-pressure gradient contact points adjacent saidmanometer;

(f) a source of electrical energy supplying said pump infiating means,said aneroid manometer, and said display panels;

(g) a pressure select switch in circuit with said aneroid manometer andsaid pump intl-ating means, said pressure select' switch being actuablewithin said aneroid manomet'er to cut off said source of electricalenergy from said pump inliating means 'at a predetermined pressure;

(h) a decompression valve in said conduit and la pressure responsiveswitch interconnecting said aneroid manometer and said valve, gaugingdecompression according as a pre-set pressure is detected in saidmanometer;

(i) Van interval control switch in circuit with said source ofelectrical energy and closing said source of energy with said pumpinating means .at predetermined intervals; and

(j) sound detecting means in communication with said cuff andindependently relayed to said visual indicia, so as to limit electricalenergization of said indicia, except as Korotkow sounds are detected.

2. A blood pressure monitor as in claim 1, wherein said sound detectingmeans includes ya microphone positionable adjacent said cuff fordetection of Korot-kow sounds, together with an independent amplifier.

3. A blood pressure monitor apparatus comprising:

(a) an inflatable cult; v

(b) pump inating means in cul;

(c) bleeder valve means positioned intermediate said pump inlating meansand said culi to allow said cuff to slowly decompress;

(d) electrically conductive pressure detecting means in communicationwith said communication with said cuff and responsive to changes inpressure therein;

(e) a display panel electrically connected to said pressure detectingmeans, said display panel including visual indicia means correspondingto pressure level ygradients of 5 mm. of Hg registered by said pressuredetecting means;

(f) a source of electrical energy supplying said cuit inating means,pressure detecting means, and display panel;

(g) sound detecting means in electrical communication with said cutf andenergized independently of said source of electrical energy supplyingsaid pump inating means, said pressure detecting means and said displaypanel so as to limit electrical energization of said indicia, except asKorotkow sounds are detected; and

(h) therapy programming means including (l) a plurality of flaskscontaining variations of medications therein together with intravenoussystems for introducing said medications into the blood stream;

(2) valve means associated with said asks for regulating the ow ofmedications therethrough; and

(3) electrical means for translating said changes in pressure determinedby said pressure detecting means into actuation of certain of said valvemeans'of said flasks, as predetermined.

4. Method of blood pressure monitoring and treatment programming,comprising:

(a) pressurizing a sound detecting cuff adjacently positioned to a bloodcontaining artery and a pressure detecting device;

(b) electrically energizing said pressure detecting device anda visualdisplay indicia so as to be responsive to changes in pressure withinsaid cult;

(c) detecting Korotkow sounds through said cu` and limiting energizationof said visual display indicia, except as Korotkow sounds are detected;and

(d) translating electrically said detected changes in pressure toregulation of introduced into the bloodstream.

5. Method as in claim 4, wherein said regulation includes automaticcycling of medications of varying strength.

6. Method as in claim 5, wherein said pressure detecting andintroduction of medications are cycled such that response to saidmedications can be gauged by said. pressure detecting device beforeintroduction of further medications.

7. Method as in claim 6, wherein said regulation includes both shocktreatment programming and pressure treatment programming.

8. Method as in claim 6, including translating electrically detectedchanges actuation of an electrocardiogram monitor.

9. Method as in claim 8,'including translating electriin pressure ofpreselected levels to actuation of alarm signal to coincide wtih cyclingof preselected medications. Y

10. A blood pressure monitor as in claim 3, including means forautomatically cycling medications from preeslected asks in response tochanges in pressure determined by said pressure detecting means.

11. A blood pressure monitor as in claim 9, including anelectrocardiogram monitor and means for actuating same as preselectedpressure level is gauged by said pressure detecting means.

12. A blood pressure monitor as in claim 11, including an alarm systemand means for actuating same as preselected pressure levels are `gaugedby said pressure detecting means.

13. A blood pressure monitor as in claim 12, including means for cyclingthe operation of said pressure detecting intravenous medications inpressure of preselected level t0 14 Pigeon 12S-2.05 Goolkasian 12S-2.05Vibber et al 128-214 De Beer et al 128-214 Kompelian 1282.05 Dymski12S-2.05 Smith 128--2.05

RICHARD A. GAUDET, Primary Examiner.

13 means and actuation of said valve means of said asks 2,848,992 suchthat response to intravenous treatment by said medi- 2,918,054 cationscan be gauged before continuing said therapy. 2,925,814 2,979,055References Cited by the Examiner 3,051,165 UNITED STATES PATENTS o2,352,875 7/ 1944 Williams 1282.05 77 2,690,178 9/1954 Bickford 128-2132,821,188 1/1958 Pigeon 12S-2.05 2,827,040 3/195s Gilford 12s-2.05 10SIMON B RODER, Examiner.

1. A BLOOD PRESSURE MONITOR APPARATUS COMPRISING: (A) AN INFLATABLECUFF; (B) PUMP INFLATING MEANS INCLUDING A CONDUIT IN COMMUNICATION WITHSAID CUFF; (C) A BLEEDER VALVE POSITIONED IN SAID CONDUIT TO ALLOW SAIDCUFF TO SO DECOMPRESS; (D) AN ELECTRICALLY CONDUCTIVE PRESSURERESPONSIVE ANEROID MANOMETER IN COMMUNICATION WITH SAID CONDUIT; (E) ADISPLAY PANEL ELECTRICALLY CONNECTED VIA A SERIES OF INDEPENDENTCIRCUITS TO RESPECTIVE PRESSURE GRADIENT CONTACT POINTS ADJACENT SAIDANEROID MANOMETER, SAID DISPLAY PANEL INCLUDING VISUAL INDICIA MEANSCORRESPONDING TO MID-PRESSURE GRADIENT CONTACT POINTS ADJACENT SAIDMANOMETER; (F) A SOURCE OF ELECTRICAL ENERGY SUPPLYING SAID PUMPINFLATING MEANS, SAID ANEROID MANOMETER, AND SAID DISPLAY PANELS; (G) APRESSURE SELECT SWITCH IN CIRCUIT WITH SAID ANEROID MANOMETER AND SAIDPUMP INFLATING MEANS, SAID PRESSURE SELECT SWITCH BEING ACTUABLE WITHINSAID ANEROID MANOMETER TO CUT OFF SAID SOURCE OF ELECTRICAL ENERGY FROMSAID PUMP INFLATING MEANS AT A PREDETERMINED PRESSURE;